Apache Web Server Forum

For some time now I've been trying to work why visitors can only download one file at a time from an Apache2 / Debian Squeeze based website of mine without having to wait for the file to complete before being able to continue browsing or download another file.

As far as I can tell there are no active limiting modules or iptables rules and MaxClients is set relatively high so I'm confused?!

Other users of what? You said you can download concurrently multiple files using direct links so it's the application that limits it. Packages can be customized or configured so I would suggest to see if there are download options for the download module you use.